Catalysis of C-C Cross-Coupling Reactions in Aqueous Solvent by Bis- and Tris(ferrocenyltriazolylmethyl)arene-β-Cyclodextrin-Stabilized Pd0 Nanoparticles

Mono-, bis-, and tris(4-ferrocenyl-1,2,3-triazolylmethyl)arene beta-cyclodextrin adducts have been used to prepare new Pd0 nanoparticle (PdNP) catalysts for CC cross-coupling reactions in EtOH/H2O. The results show that these catalysts work well in MiyauraSuzuki and Heck reactions with iodoarenes at 25 and 80 degrees C, respectively, with turnover numbers (TONs) of up to 31000 for standard MiyauraSuzuki reactions of PhI when 10 ppm of the Pd catalyst (5 nm PdNPs) were used. The results show the benefit for PdNP catalysis of encapsulating hydrophobic catalytic systems between peripheral water-solubilizing cyclodextrins as bolamphiphile-like materials because the open monoferrocenyltriazolylmethylbenzene system shows a considerably reduced catalytic efficiency compared with bis- and tris(4-ferrocenyl-1,2,3-triazolylmethyl)arene beta-cyclodextrin adducts.